Upload
lamminh
View
225
Download
0
Embed Size (px)
Citation preview
mosen
The New PIARC Tunnel Air
Emissions Standard
Dr Fathi Tarada
PIARC Working Group on Air Quality, Fire
and Ventilation
mosen
Motivation
• Air quality is an important criterion for
tunnel ventilation
• Design emissions data requires updating
• Reconsideration of critical pollutants
• Guidelines for developing countries &
countries in transition
• Improvements in the design, specification
and operation of tunnel ventilation
mosen
Authors
The authors of the PIARC report on “Road Tunnels: Vehicle Emissions
and Air Demand for Ventilation” are
• Rune Brandt (Denmark/Switzerland)
• Romano Borchiellini (Italy)
• Bruce Dandie (Australia)
• Arnold Dix (Australia)
• Massimiliano Fresta (Italy)
• Frédéric Hervé (France)
• Mathias Henn (Austria)
• Norris Harvey (USA)
• Peter Sturm (Austria)
• Franz Zumsteg (Switzerland)
mosen
Agenda
2. Critical Pollutants
4. Calculations Procedures
5. Summary
6. Conclusions
3. Vehicle Emissions Standards
1. Background
mosen
1. Background
mosen
Purpose of Tunnel Ventilation
• To control smoke movement in case of a
fire within a road tunnel (usually the
dominant factor)
• To ensure adequate air quality within a
road tunnel, during normal and congested
operation (may be dominant in highly
trafficked urban tunnels)
The current report only addresses air quality
issues, not smoke control.
mosen
Previous PIARC Reports
• Report from 2004 “Road Tunnels: Vehicle
Emissions and Air Demand for Ventilation”
• Report from 1995 “Vehicle Emissions - Air
Demand, Environment, Longitudinal
Ventilation”
New report replaces both previous reports.
mosen
2. Critical Pollutants
mosen
Critical Pollutants
• Fresh air demand is estimated based upon
in-tunnel production of critical pollutants:
– Carbon monoxide (CO)
– Visibility (suspended dust)
– NOx (including NO2)
Need to reduce the pollution concentrations
to acceptable levels.
mosen
Carbon Monoxide (CO)
• Traditionally taken as the reference
emission for the assessment of the toxicity
of exhaust gases
• Declining in importance due to
– Improvements in engine design
– Increasing proportion of diesel-powered
vehicles
mosen
Visibility & Dust
• Vehicle exhaust (mostly from diesel
engines) consists of very small particles
mainly in the range of 0.01 to 0.20 µm.
Particles in this range are very effective in
light extinction.
• Also: particulate matter due to abrasion
processes (road, tires, brake wear, etc.)
and re-suspension of road dust (1 µm and
upwards – less effect on visibility)
mosen
Nitrogen Oxides
• NO2 is noxious and can irritate the lungs
and lower the resistance to respiratory
infections such as influenza.
• Better engine design reduces nitrogen
oxide emissions, but
• Implementation of diesel vehicle exhaust
gas after-treatment systems increases
proportion of NO2 from 10% up to 30%
mosen
DESIGN AND THRESHOLD VALUES
Traffic situation CO Visibility/Extinction Visibility/Transmission
ppm 10-3 m-1 % (beam length 100m)
Free flowing peak traffic50 –
70 5 60
Daily congested traffic, stopped on all lanes 70 7 50
Exceptional congested traffic, stopped on all
lanes100 9 40
Planned maintenance work in a tunnel under
traffic20 3 75
Threshold values for closing the tunnel 200 12 30
mosen
3. Vehicle Emissions Standards
mosen
Vehicle Emissions Standards
• Regional & national variation in emissions
standards
• EC EURO-standards implemented in
Europe, in many countries of Asia (except
Japan and South-Korea) and in a few
countries in South America, Africa and the
Arabic countries.
• Euro 5 effective 1st Jan, 2010 and Euro 6
effective 1st Jan, 2014.
mosen
Evolution of Euro Standards
Valid CO HC NOx HC+NOx Particles
[g/km]
ECE R 15/03 1979 21.5 1.8 2.5 smoke number
ECE R15/04 1982 16.5 5.1 smoke number
US 83* 1987 2.1 0.25 0.62 0.373
PC Euro 1 1992 2.72 0.97 0.14
PC gasoline EURO 2 1997 2.2 0.5
PC gasoline EURO 3 2000 2.3 0.2 0.15
PC gasoline EURO 4 2005 1.0 0.1 0.08
PC gasoline EURO 5 2008 1.0 0.100 0.060 0.068 0.005
PC gasoline EURO 6 2014 1.0 0.100 0.060 0.068 0.005
mosen
Vehicle Emissions Standards
• US emissions standards: National “Tier II”
standards (from Environmental Protection
Agency), Californian Air Resources Board
(CARB)
• Other countries and regions have their
own emissions standards.
mosen
International Survey
• Questionnaires sent out to World Road
Association member countries
• Based on the information received,
emission factors for certain countries were
derived (Australia, Algeria and China)
mosen
Emissions Tables (Example)
mosen
4. Calculations Procedures
mosen
Emissions Calculations
• Previous PIARC emissions calculations
were based on the projected vehicle-fleet
distribution (passenger cars, light duty
vehicles and heavy goods vehicles) and
individual emission standards
• However, this information is not always
readily available in developing countries
and countries in transition
mosen
Changes Proposed
• In addition to previous calculation scheme,
a simplified scheme based on Technology
Standards will be proposed.
• Use 2010 as the base year adjusted with
country-specific influencing factors
concerning different design years,
emission standards, etc.
mosen
Technology Standards
Technology standard A:
• Covers the European Union, USA and
countries with similar vehicle emission
standards.
mosen
Technology Standards
Technology standard B:
• Countries which have adopted Euro or
similar emission standards with a time shift
of 10 years.
Technology standard C
• Countries which have adopted emission
standards but don‟t conduct any effective
emission control.
mosen
5. Summary
mosen
Summary
• Complete review of previous PIARC
recommendations on air quality demands
• Increasingly, NOx and dust are becoming
more critical than CO for tunnel air quality
• New scheme proposed with „technology
standards‟ to supplement vehicle-specific
calculations.
mosen
Summary
• Some details of the new standard are
available to download via
mosenltd.com/news
mosen
6. Conclusions
mosen
Conclusions
• The new PIARC standard is aimed to
improve air quality in tunnels worldwide
• Will be published later this year (2011)
• Please use it and feed any comments
back to the PIARC Secretariat!